package miggy.cpu.instructions.move;

import miggy.api.cpu.Size;
import miggy.api.cpu.DecodedInstruction;
import miggy.cpu.DecodedInstructionImpl;
import miggy.SystemModel;
import miggy.cpu.operands.OperandFactory;

/*
//  Miggy - Java Amiga MachineCore
//  Copyright (c) 2008, Tony Headford
//  All rights reserved.
//
//  Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
//  following conditions are met:
//
//    o  Redistributions of source code must retain the above copyright notice, this list of conditions and the
//       following disclaimer.
//    o  Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
//       following disclaimer in the documentation and/or other materials provided with the distribution.
//    o  Neither the name of the Miggy Project nor the names of its contributors may be used to endorse or promote
//       products derived from this software without specific prior written permission.
//
//  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
//  INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
//  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
//  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
//  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
//  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
//  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// $Revision: 21 $
*/
public class MOVEP
{
	public final int execute(int opcode, Size size)
	{
		int dreg = (opcode & 0x0e00) >> 9;
		//signed displacement - not 100% sure in this case
		int displacement = (short)SystemModel.CPU.fetch(Size.Word);

		int address = SystemModel.CPU.getAddrRegister(opcode & 0x0007) + displacement;

		if((opcode & 0x0080) != 0)
		{
			//reg to mem
			int dval = SystemModel.CPU.getDataRegister(dreg);

			if(size == Size.Long)
			{
				SystemModel.MEM.poke(address, (dval >> 24), Size.Byte);
				SystemModel.MEM.poke(address + 2, (dval >> 16), Size.Byte);
				address += 4;
			}
			SystemModel.MEM.poke(address, (dval >> 8), Size.Byte);
			SystemModel.MEM.poke(address + 2, (dval), Size.Byte);
		}
		else
		{
			//mem to reg
			int dval = 0;

			if(size == Size.Long)
			{
				//test: changed to peek
				dval = SystemModel.MEM.peek(address, Size.Byte) << 24;
				dval |= SystemModel.MEM.peek(address + 2, Size.Byte) << 16;
				address += 4;
			}
			dval |= SystemModel.MEM.peek(address, Size.Byte) << 8;
			dval |= SystemModel.MEM.peek(address + 2, Size.Byte);

			SystemModel.CPU.setDataRegister(dreg, dval, size);
		}

		return (size == Size.Long ? 24 : 16);
	}

	public final DecodedInstruction decode(int address, int opcode, Size size)
	{
		DecodedInstructionImpl di = new DecodedInstructionImpl("movep" + size.ext(), opcode, address, size);
		//signed displacement
		int displacement = (short)SystemModel.MEM.peek(address + 2, Size.Word);

		if((opcode & 0x0080) == 0)
		{
			di.setSrc(OperandFactory.addrIndDisplace((opcode & 0x0007), displacement));
			di.setDst(OperandFactory.dataReg((opcode & 0x0e00) >> 9));
		}
		else
		{
			di.setSrc(OperandFactory.dataReg((opcode & 0x0e00) >> 9));
			di.setDst(OperandFactory.addrIndDisplace((opcode & 0x007), displacement));
		}
		return di;
	}
}
